Retry direct unix package calls if observing EINTR

Retry Recvfrom, Sendmsg, Readmsg, and Read as they can return EINTR.

Signed-off-by: Evan Phoenix <evan@phx.io>

libcontainer/notify_v2_linux.go

@@ -2,6 +2,7 @@ package libcontainer
 
 import (
 	"fmt"
+	"os"
 	"path/filepath"
 	"unsafe"
 
@@ -40,7 +41,11 @@ func registerMemoryEventV2(cgDir, evName, cgEvName string) (<-chan struct{}, err
 
 		for {
 			n, err := unix.Read(fd, buffer[:])
+			if err == unix.EINTR { //nolint:errorlint // unix errors are bare
+				continue
+			}
 			if err != nil {
+				err = os.NewSyscallError("read", err)
 				logrus.Warnf("unable to read event data from inotify, got error: %v", err)
 				return
 			}